RU2469809C9 - Method of contouring preset length tube - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: proposed metal comprises placing tube 2 between, at least, one pair 4 of rolls 5 with parallel rotational axes 6, arranged across tube 2, and radial displacement with gradual pressing of rolls 5 to tube 2. At the same time, tube 2 reciprocates axially. Decreased tube ovality and higher roll crosswise stability due to axial forces acting thereto are ensured by simultaneous roll radial transfer and tube reciprocation.

EFFECT: higher tube quality and equipment durability.

11 cl, 9 dwg

Description

FIELD OF THE INVENTION

The present invention relates to a method for profiling a pipe of a given length, in particular a metal pipe obtained by cutting a pipe of an indefinite length in the transverse direction at the end of a continuous production process.

State of the art

For profiling metal pipes of a given length and section, various methods are used to convert the initial section of the pipe into another, for example, round, square, rectangular, lobed, star-shaped, etc., section.

One of the most common methods is to pass the pipe through a plurality of shaped dies located on one line in a predetermined direction of movement of the pipe and each of which includes a plurality of rolls arranged to form a passage for the pipe.

The sections of successive passages differ from each other and more and more approach, in the direction of movement of the pipe, to the final section of the pipe, so that the pipe, when passing in the direction of movement, gradually deforms from the original to the final specified section.

The above method provides profiles of good enough quality, however, it has several disadvantages that seriously impair production.

One of them is incorrect deformation of the front end section of the pipe when the pipe is inserted between the rolls of dies. As a result of this, the end section must be removed at the end of the profiling process, which thereby affects the additional costs associated with equipment and waste.

Another disadvantage of this method is that shaped dies are usually designed for a specific pipe size and a certain final section, so that for each specific initial pipe size and / or each specific final section, all or some of the dies must be replaced, thereby causing additional costs associated with downtime and the high cost of the necessary equipment.

To eliminate the last of these drawbacks, which undoubtedly becomes worse, the larger the pipe will be, another method was proposed in which all the dies, or at least all those that are installed between the original draft dies and the final finishing dies, were replaced with many pairs opposite located rolls movable with respect to each other and within a given interval in the radial direction relative to the axis of the pipe.

Despite the great flexibility, being sufficiently adaptable to the size and shape of the pipe, this solution cannot eliminate the first of the drawbacks mentioned above regarding improper deformation of the front end section of the pipe.

A solution to this problem is proposed in WO-A-2008/022626, which discloses the transmission of a pipe between a pair of rolls located at a distance from each other, which then converge in the middle section of the pipe and are located at a distance from each other that is smaller than the outer diameter of the pipe which is heated to ensure radial penetration of the rolls. Then the pipe makes a reciprocating movement between the rolls to obtain deformation of the above middle section of the pipe. The final shape of the pipe is achieved by phasing the gap between the rolls.

The above solution has several drawbacks, mainly because the radial load applied by the rolls to the pipe, at any stepwise adjustment of the gap, is a static radial load, which will cause the pipe to ovality if the pipe is not heated. In addition, the axial forces necessary to start moving the pipe in the axial direction are so great that the lateral stability of the rolls is always at risk.

Disclosure of invention

The present invention is to provide a method for profiling pipes of a given length, which is inexpensive and easy to implement and, at the same time, provides the elimination of the above disadvantages.

In accordance with the present invention, there is provided a method for profiling a pipe of a given length, as claimed in the appended claims.

Brief Description of the Drawings

Many non-limiting embodiments of the present invention will be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a schematic perspective view of a preferred embodiment of a device for profiling a pipe of a given length and implementing a method in accordance with the present invention.

FIG. 2-6 are schematic perspective views of the implementation of respective embodiments of the device of FIG. one.

FIG. 7 is an enlarged cross-sectional view of the device of FIG. 6.

FIG. 8 and 9 are similar to FIG. 7 and are cross-sections of the respective embodiments of FIG. one.

Preferred Embodiments

Reference numeral 1 in FIG. 1 designates a device for profiling a pipe 2 of a predetermined length L.

As an example, pipe 2 in FIG. 1 has an initially circular cross section coaxial to the longitudinal axis 3 and to be converted into a substantially square cross section.

The device 1 has many pairs of 4 opposite rolls 5 spaced along the axis 3, and in the pipe 2 at a length shorter than length L.

The rolls 5 in each pair 4 are identical, are located on opposite sides of the axis 3, rotate around the corresponding parallel, the axes 6 lying in the same plane are transverse to the axis 3, each roll has a cylindrical working surface and a length of at least equal to the side of the specified final cross section.

The pairs of 4 rolls 5 are arranged in alternating order at an offset angle of 90 ° relative to axis 3. In other words, the working surfaces of the rolls 5 in each pair 4 are turned towards the corresponding sections of the pipe 2 at an angle of 90 ° to the sections facing the working surfaces of each of the adjacent pairs 4.

The rollers 5 in each pair 4 are mounted with the possibility of regulation on the respective bearings (not shown) and are made with the possibility of gradual movement relative to each other and radially relative to the axis 3, between the open position in which the corresponding working surfaces are spaced by a distance d , measured by the distance between the centers equal to or greater original diameter of the tube 2, and a closed position in which the distance d between the respective work surfaces of rolls 5 equals the length of a predetermined side qua selfless cross section.

The rollers 5 are moved in the radial direction using actuators (not shown), which are controlled by a central electronic control unit (not shown) and which can be represented, for example, by known lifting devices, known hydraulic cylinders or other similar power drive systems of known designs and principles actions and therefore are not described in detail.

The rolls 5 in pairs 4 are driven by reversible electric or hydraulic motors (not shown) to rotate them in both directions around the corresponding axis 6. In another embodiment, some rolls 5 are moved and others are inoperative.

In practical use, at the beginning of the profiling process, the rolls 5 in each pair 4 are installed in the open position to form a through channel that is wider than the original circular cross section of the pipe 2.

The pipe 2 is then installed between the rolls 5, with the axis 3 of the pipe being located essentially transverse to the axis 6, and the cylindrical side wall 8 of the pipe is essentially equidistant from the working surfaces of the rolls 5.

After installing the pipe 2, the rolls 5 in each pair 4 are moved in the radial direction with respect to the axis 3, close to the pipe 2, and rotate in opposite directions around the corresponding axes 6.

Upon reaching the side wall 8, the rolls 5 begin to compress and deform the side wall 8, and at the same time, press the pipe 2 axially in the same direction as the direction of rotation of the rolls 5 at the point of contact with it. When the rear end of the pipe 2, in the direction of movement of the pipe 2, reaches the last pair 4, the rotation of the rolls 5 is reversed, and the pipe 2 moves axially in the opposite direction.

As the pipe 2 moves back and forth, as described above, the rolls 5 in all pairs 4 gradually compress the side wall 8 simultaneously, so that the combined action of the pressure of the rolls 5 and the axial movement of the pipe creates a gradual and uniform deformation of the side wall 8.

Profiling ends when the rollers 5 reach a closed position in which the cross section of the passage formed by the pairs 4 generally corresponds to a predetermined final cross section of the pipe 2, and the entire pipe 2 has a uniform deformation.

After that, the pipe 2 can be freed from the rolls 5, which are then re-set to the open position to receive the next pipe 2. On the other hand, the rolls 5 can be re-set to the open position before removing the pipe 2, in this case manually.

In connection with the foregoing, it should be noted that the initial position of the pipe 2 is in no way mandatory, and the central portion of the pipe 2 need not be located within pairs 4, as described in the example. For example, if the pipe 2 is initially located so that its end section is opposite the pairs 4, then you just need to change the first axial movement of the pipe 2 so that the deformation by the rollers 5 is "distributed" along the entire length of the pipe 2.

In this regard, it should be noted that, contrary to conventional profiling methods, the described method also has the advantage of providing profiling of a section of pipe 2 of any length equal to or less than length L , or two or more separate sections of pipe 2 by programming a central control unit (not shown) for the appropriate control of the rotation of the rolls 5 and the radial movement of the opening and closing pairs 4. In this case, the rolls 5 must be returned to the open position before the pipe 2 is removed from the rolls 5 in Onze profiling process.

It should be noted that the above method with respect to device 1 in FIG. 1 applies regardless of the number and location of rolls 5.

For example, in the embodiment of FIG. 2, device 1 includes, in addition to the pairs 4 shown in FIG. 1, two shaped dies 7 located at the respective ends of the pairs 4 and each of which includes four identical coplanar rolls 5 located in the form of two opposite pairs and forming a passage A, coaxial to the axis 3.

In the embodiments of FIG. 3 and 4, device 1 includes a plurality of dies 7 aligned along axis 3, and one dies 7, respectively.

In order to maximize the versatility of the device 1, it is preferable to use “universal” dies as dies 7, namely those in which the rolls 5 can take various closed positions, each of which corresponds to a certain size of a given final cross section. Like pairs 4, rolls 5 of each stamp 7 are mounted on supports (not shown) and are radially adjusted relative to axis 3.

In the embodiment of FIG. 5, the device 1 includes one pair of 4 rolls 5. This solution has a great advantage, being simple, compact and cheap, however, the processing of the entire outer surface of the pipe 2 requires stepwise profiling and rotation of the pipe 2 around axis 3 between one and the other for selective arrangement of adjacent sections of the side wall 8 opposite the working surfaces of the rolls 5.

It should also be noted that the described method with respect to the device 1 is also applied regardless of the shape of the rolls 5 and / or dies 7, that is, regardless of the shape of the required final cross section.

For example, as can be seen from FIG. 7 and 9, the final lobular cross-sections of various types can be obtained by using rolls 5 of the appropriate shape, located with a corresponding offset relative to axis 3.

In conclusion, in FIG. 6 shows a variant of the method described above, by which a pipe 2 with a helical lobular cross-section, which cannot be obtained using traditional methods, is obtained.

In this case, the rolls 5 have corresponding inclined axes 6 relative to the axis 3 of the pipe 2, so that the pipe 2 rotates in one and the other side simultaneously and at the same time with its axial reciprocating movement.

In this regard, it should be noted that in another embodiment, all the rolls 5 can be non-driven, and the pipe 2 can be moved in the axial direction and rotated in one or the other direction using one or more actuators (not shown) controlled by a central electronic control unit ( not shown).

Claims (11)

1. A method for profiling a pipe (2) having a predetermined length (L), a longitudinal axis (3) and a side wall (8) substantially coaxial with the longitudinal axis (3), comprising arranging at least one pair (4) of opposite rolls ( 5) having the corresponding axis of rotation (6), with the formation of the passage (A) for free reception of the pipe (2), the introduction of the pipe (2) into the passage (A) with the location of its longitudinal axis (3) across the axis of rotation (6), the movement of the rolls (5) radially relative to the longitudinal axis (3) until it contacts the side wall (8) of the pipe, then gradually presses the roll (5) to the side wall (8) (2) and the pipe axial reciprocating movement of the pipe, characterized in that the radial movement of said rollers (5) and an axial reciprocating movement of the pipe (2) is carried out simultaneously. 2. The method according to claim 1, which includes an additional step of rotating the pipe (2) in one and the other side around its longitudinal axis (3), while the rotational and axial movements are carried out together to obtain a screw movement. 3. The method according to claim 2, in which the rotational movement of the pipe is performed simultaneously and during its axial reciprocating movement. 4. The method according to any one of claims 1 to 3, in which a plurality of pairs (4) of rolls (5) are displaced relative to each other by a predetermined angle along the longitudinal axis (3) of the pipe (2), while radial movement is reported to the rolls ( 5) in all pairs (4). 5. The method according to claim 4, in which at least two pairs (4) of rolls (5) are installed with the formation of a shaped stamp (7). 6. The method according to claim 1, in which the rolls (5) are driven, while the pipe (2) is moved axially by means of the rolls (5) and axial reciprocating is carried out by reversing the rotation of the rolls (5). 7. The method according to claim 1, which includes an additional step of withdrawing the rolls (5) radially from the pipe (2) to change the passage (A) and at least partially remove the shaped pipe (2) from the passage (A). 8. The method according to claim 1, in which the axial reciprocating movement is shorter in length than the length (L) of the pipe (2) and covers a given section of the pipe (2). 9. The method of claim 8, wherein the predetermined portion is a central portion. 10. The method of claim 8 or 9, in which the specified section contains at least two separate consecutive sub-sections. 11. The method according to claim 1, in which the radial movement of the rolls (5) and axial movement of the pipe (2) is controlled electronically.

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